1. Field of Invention
The present invention relates to a fluid discharge device that supplies fluid from a removable fluid tank to a head from which fluid is discharged, a control method for the fluid discharge device, and a fluid tank.
2. Description of Related Art
A common type of fluid discharge device is an inkjet printer that supplies ink from a removable ink cartridge to a recording head, and discharges the ink from the recording head to print on paper.
When the ink is consumed by printing and an empty cartridge or no-ink state is detected by a sensor in this type of printer, a trademark logo is overwritten by a writing device or a single black line is added to a number-of-uses label before the ink cartridge is removed from the ink cartridge holder so that the ink cartridge cannot be used until a new replacement label is applied over the logo, and the ink cartridge is prevented from being reused again after the number-of-uses label is completely filled in when the ink cartridge has been refilled the maximum number of times. See, for example, Japanese Unexamined Patent Appl. Pub. JP-A-2003-11469.
This device enables confirmation from the label on the removed ink cartridge of whether or not the ink cartridge can be used, but because a reading sensor and a writing device are needed to read and write information on the trademark logo or the number-of-uses label, the parts count increases and the construction becomes more complicated, which leads to a higher product cost.
In addition, when the label becomes soiled or smudged with ink, the ink information cannot be read accurately by the reading sensor, and the printing process may be needlessly interrupted.
Furthermore, while whether there is ink in the cartridge and whether the ink cartridge can be used can be confirmed from the trademark logo or the number of uses label, how much ink is left cannot be accurately determined.
It is also conceivable to provide a small transparent window on the container part of the ink cartridge to enable a visual confirmation of how much ink is left or detection of whether ink is left using an optical sensor, but this requires that part of the ink storage pack inside the ink cartridge also be transparent, resulting in greater structural complexity. Furthermore, because the gas barrier performance of the materials used to form the transparent container or pack is poor, and ambient light incident to the ink can easily cause the color to change, the ink storage performance of such transparent materials is not good.
It is also conceivable to dispose an IC chip in the ink cartridge so that ink information can be written and read from the IC chip, but how much ink is left in the ink cartridge cannot be confirmed when the ink cartridge is removed from the printer. As a result, if multiple ink cartridges become mixed together, each ink cartridge must be loaded into the printer in order to confirm how much ink is left in each cartridge, and this is obviously tedious and time-consuming.
In such situations it is common for the user to shake the ink cartridge or guess how much ink is left based on the weight, but accurately determining how much ink is left is difficult with such methods. There is also little change in weight with ink cartridges that internally recover the ink used to clean the print head as waste ink, making it particularly difficult to determine how much usable ink is left based on weight.